By Dr. Ananya Mandal, MD Jan 8 2020
In a new study, researchers from UCL Cancer Institute have found that a subset of immune cells are capable of killing cancer cells when they are activated. This could lay the foundation stone for effective anti-cancer therapies believe the researchers. Image Credit: Christoph Burgstedt / Shutterstock.com
The study titled, "Regulatory T cells restrain Interleukin-2 and Blimp-1-Dependent acquisition of cytotoxic function by CD4+ T cells" was published in the latest issue of the journal Immunity on the 7th of January 2020. Activation of immune cells upon immunotherapy
This study was led by Professors Sergio Quezada and Karl Peggs, who had conducted previous research on the same theory, have found that when the immune system is subjected to immunotherapy, some of the cells are activated.
These activated CD4+ T cells were initially thought to be helper cells and regulate the immune cells. When activated, these cells have been found to become killer cells and directly kill the cancer cells. This has been proven in animal studies on lab mice, the authors wrote. Study results
The study funded by the Cancer Research UK was an in-depth analysis of what happened at the cellular level, in order to see what the immune cells do to cancer cells. The cellular mechanisms of these activities have been outlined in this research.
Results revealed that in the T cells, a growth factor called Interleukin 2 (IL-2) was the main factor behind the cytotoxic or cell killing activities. This was aided by the 'transcription factor' Blimp-1. Both of these factors are responsible for starting the killer activities of the CD4+ T cells within the cancers.
We knew these immune cells had the ability to proactively kill cancer cells with incredible potency, but to maximize their potential, we needed to know how this mechanism was activated. Our discovery provides the evidence and rationale for utilising Blimp-1 to maximise the anti-tumour activity of CD4+ T cells. Work is now underway in our lab to develop new personalized cell therapies where the activity of Blimp-1 can be maxed up to drive potent tumor control." Professor Sergio Quezada, UCL Cancer Institute
The team explained that T-type lymphocytes are generally the attacker cells of the immune system, killing infected cells around the body. These cells, however, are normally incapable of killing cancer cells because cancer cells are made up of the body's own cells. When these T cells are activated using immunotherapy, they are modified so that they can attack cancer cells. The actual challenge of immunotherapy thus lies in activating the T cells, explained the researchers. Mouse models of cancer